While everyone got a peek at Kendall Jenner‘s front, Khloé Kardashian had her back.

The 18-year-old walked the runway for Marc Jacobs Thursday in a sheer top that showed most of her breasts to the crowd, inciting online catcalls from haters, calling her less than demure. That’s when her older sister sprang into action, defending the teen for the artsy display during New York’s Fashion Week.